20g Long Sump - Baffle Question

[Ryan S]

I have a 150g display tank, with a 20g long sump. An Avast CS1 pegleg skimmer is going on one end of the sump, which will have 2 chambers divided by 3 baffles to stop microbubbles. The baffles will be 1" apart. The skimmer chamber will be 10" wide, leaving 20" for the return pump side and the 3 baffles (approx 17" for the return pump side itself). The avast skimmer will probably be recirc, so the height of the water on that side won't matter. My question is, how high should I place the float valve and the first baffle, which will determine the maximum height of the water in the return pump side of the sump? Initially I was thinking an 8" baffle and placing the float valve at the 7.5"? I want maximum water in the return pump side so the ATO isn't going off constantly, but also need enough room when the power goes out... A 20g long tank is 12" tall. Should I go 7", 8", 9"?

[wvreef]

Ok first off I would not go with a 20 long for my sump, now this is just me... My 180 drops around 15 gallon when the power goes out to my sump below...I have a 55 gallon sump under my 180 with about 10 inches of water in it at all times...

 

How much water do u think your 150 will drop when water is off? I calculated mine buy going to my overflows and measuring down how much will go in them and added a 1/2inch for good measure (just in case) then took all the measurements and pluged them into a aquarium calculator to get me total water dropping down....now keep in mind you will have around 2.5 gallons in skimmer give or take and any other plumbing....

when you figure out how much is dropping down you can figure your water hight in your sump....make sure you give yourself 2-3 inches from the top just to be safe....you never know what might happen

 

also I have my ato floats setting at the same height so my ato is filling my sump on and off all the time...I like this because it keeps everything in check like salinity and such...

Edited January 24, 2012 by wvreef

[Ryan S]

there are holes in the durso overflows that came with the marineland tank, but there is no way for me to know how much would drain without filling the tank, hooking up the plumbing, and the return pump, is there?

 

couldn't i just drill holes higher on the overflow to break the siphon in a power failure, after only a couple of gallons have fallen to the sump?

[Der ABT]

he has an overflow so you can just put a riser pipe inside the overflow and decrease the amount of water that is drawn back in aka raise the level inside the overflow...this also quiets things down alot as the water doesnt have a long way to fall.

thats how i did my 75 at least and it was basically only the water left in the plumbing that would fill the tank...as long as the return had no siphon obviously.

 

i would say wait for the float valve till you can do a little testing. all the math in the world is great but when you actually do something there is some variable you will have missed.

[Der ABT]

other things to think about is how tall is your return pump...some pumps suck air just above their actual height...i think you planned an a mag 9.5 and they dont do that so much.

 

make sure you leave room for the inlet to the skimmer in that chamber and then put the two baffles in.... for the third baffile put it higher then you think you want. you can always cut it after you siliconed it in there if you use acrylic.

 

just get the water outta the sump and dremel it to the level you want.

 

having the extra room for water in the return side wont matter on how often the ato goes off...if its a good ato (avast,tunze, whatever) it will be pretty sensitive just a warning to ya.

[trockafella]

I agree with WVReef, I have a 20 long sump for my 70 gal, and when the power goes it fills up even higher than I expected. I dont have my return nozzle that far below water either. The 29 might be a better choice for the extra height. Better to play it safe.

[steveoutlaw]

I would make your return pump area just big enough to fit the return pump. Here is how I did mine:

 

[Ryan S]

he has an overflow so you can just put a riser pipe inside the overflow and decrease the amount of water that is drawn back in aka raise the level inside the overflow.

thats how i did my 75 at least and it was basically only the water left in the plumbing that would fill the tank...as long as the return had no siphon obviously.

 

this sounds like what i want and need. i only want the water in the plumbing to fall down, so no more than 5g ideally. but i have no idea what you just said really lol. you'll have to come over and show me when i am closer to adding water to the tank.

 

I agree with WVReef, I have a 20 long sump for my 70 gal, and when the power goes it fills up even higher than I expected. I dont have my return nozzle that far below water either. The 29 might be a better choice for the extra height. Better to play it safe.

 

The stand is only 24" tall underneath, so a 19" tall 29g tank just wouldn't be practical. I wouldn't be able to remove the skimmer, etc. And working inside would suck. So if a 20g tank won't work... I'll definitely have to figure something else out.

 

I would make your return pump area just big enough to fit the return pump.

 

but I thought I wanted the return side as large as possible, since this is what fluctuates with evaporation?

[steveoutlaw]

but I thought I wanted the return side as large as possible, since this is what fluctuates with evaporation?

 

You dont' want the water to fluctuate. That's why you want an ATO so when you start to get some evaporation, the ATO kicks on and refills. The only time your levels are going to fluctuate is when you cut your main pump off.

[beatle]

What size is your 150? Is it a 6 ft tank? If so, I would recommend a 4 ft sump. A 40 long would be about as tall as your 20, but twice as long. If it's not a 6 ft tank, what are its dimensions?

 

I agree with Steve on making the return area as small as possible. An ATO will take care of the evaporation.

[Ryan S]

What size is your 150? Is it a 6 ft tank? If so, I would recommend a 4 ft sump. A 40 long would be about as tall as your 20, but twice as long. If it's not a 6 ft tank, what are its dimensions?

 

I agree with Steve on making the return area as small as possible. An ATO will take care of the evaporation.

 

it's a marineland 150g DD. it's 36"x36". the inside dimensions of the stand are 31"x31"x25".

Edited January 24, 2012 by Ryan S

[beatle]

Ah, that's tougher then. I would get a custom acrylic sump in that case. You could easily get a 40-50 gallon container in there.

[steveoutlaw]

Ryan - I found this on RC. This is a good representation of proportions. Just look at the big area as your skimmer / live rock area. I wouldn't recommend putting the water level this high. Determine the optimum water level for your skimmer and make that your water level for the sump.

 

Edited January 24, 2012 by steveoutlaw

[Ryan S]

Thanks Steve. According to that diagram, I don't need 3 baffles, just 2, is that enough to prevent microbubbles?

 

As for ideal water height for the skimmer. It's 7" for the Avast CS1 Skimmer, but if I get the recirc mod, then it doesn't matter at all, so what then? Run it low, say 4", then I know the sump can hold more in a power failure?

[Ryan S]

Anti Siphon Hole

 

I found this image. If I drill 2 holes at this location on the return that goes into my tank, would that prevent a lot of water from back siphoning? Any reason not to make these holes?

Edited January 26, 2012 by Ryan S

[Ryan S]

I also found this link, and want to run this guy's math by you guys. Does his math hold water?

 

With my tank...

 

150 gallon tank, (36Lx36Wx27H, actually 151.480 gallons)

20 gallon sump, (30Lx12Wx12H, actually 18.701 gallons)

 

If you're return pipe sits 1 inch below the surface of the display, it will backsiphon 5.610 gallons of water (36Lx36Wx1H =1296. Divided by 231 = 5.610). So you need to make sure your sump can handle an additional 5.610 gallons of water.

 

To measure what your sump needs to be able to handle, we start calculating what it takes it add one inch of extra water in your sump. IE for the 20 gallon tank used as a sump in the example, it would be like this, 30Lx12Wx1H and divide the answer by 231 = 1.558 gallons per inch of water added to your 20 gallon sump.

 

So in order to handle an additional 5.610 gallons of water in your sump without flooding, you need to make sure your sump water level is at least 3.600 inches below the top of the sump at all times, (5.610 divided by 1.558 = 3.600), or you could just call it four and give yourself some wiggle room.

 

***************

 

So according to this guy's math, if I put my float valve at the 8" mark in the sump, I should be okay in a power failure?

Edited January 26, 2012 by Ryan S

[John]

Don't forget to account for equipment in the sump that will displace water volume...

[beatle]

You may want to budget for the overflow box as well. Typically standpipes are not glued into the bulkhead and water can leak past them and drain the box. Or if you wanted to clean the overflow box or catch a trapped fish, you may need to remove the standpipe. That water will end up in your sump.

 

Though I haven't met anyone who would recommend this, you could consider the use of a check valve on your return. When working properly, they keep water from flowing backwards. The trouble is that when they fail and you haven't "budgeted" for the backsiphon, you end up with a spill. Most people use them for convenience or extra insurance. Something to consider, depending on how much risk you want to take on. BRS sells a pretty good one, but they are not inexpensive: Personally, I'd still go the custom acrylic sump route. I think Jeff Haddock is still in the biz.

[Ryan S]

Though I haven't met anyone who would recommend this, you could consider the use of a check valve on your return. When working properly, they keep water from flowing backwards. The trouble is that when they fail and you haven't "budgeted" for the backsiphon, you end up with a spill. Most people use them for convenience or extra insurance. Something to consider, depending on how much risk you want to take on. BRS sells a pretty good one, but they are not inexpensive: Personally, I'd still go the custom acrylic sump route. I think Jeff Haddock is still in the biz.

 

Thanks Matt. I am going to add that check valve to my current BRS order. My tank will definitely have plenty of redundancy. I'll leave the return lines near the top of the water; make holes just above the water line on them; use the check valve; and make sure the sump can handle the water from the DT in a power failure. That way there are multiple fail mechanisms in place, and if the holes get clogged or the check valve fails, the sump can still handle the water volume. That seems pretty safe.

 

With that said, when it comes to plumbing under my tank, I was hoping to run the lines at the top of my stand, and hang them with brackets or something, so I would have maximum space to work with under the stand still. If I install the return line from the DT in the corner, and it has a union, then the check valve, it's going to be pretty far down vertically in the corner of my stand. Does anyone know if it would be ok to install a couple 90 degree elbows after the check valve to bring the pipe back to the top of the stand, so i can then run it across to the return pump (and feed the reactors on the way)?

Edited January 26, 2012 by Ryan S

[Ryan S]

Thanks Matt. I am going to add that check valve to my current BRS order. My tank will definitely have plenty of redundancy. I'll leave the return lines near the top of the water; make holes just above the water line on them; use the check valve; and make sure the sump can handle the water from the DT in a power failure. That way there are multiple fail mechanisms in place, and if the holes get clogged or the check valve fails, the sump can still handle the water volume. That seems pretty safe.

 

With that said, when it comes to plumbing under my tank, I was hoping to run the lines at the top of my stand, and hang them with brackets or something, so I would have maximum space to work with under the stand still. If I install the return line from the DT in the corner, and it has a union, then the check valve, it's going to be pretty far down vertically in the corner of my stand. Does anyone know if it would be ok to install a couple 90 degree elbows after the check valve to bring the pipe back to the top of the stand, so i can then run it across to the return pump (and feed the reactors on the way)?

 

On second thought, I will be skipping the check valve. I think the other precautions should be enough!

[Ryan S]

How does this sump plan look?

 

 

The return pump section holds 2g of water; so with my ATO on a timer, that should be plenty of water to cover evaporation between ATO runnings.

 

The empty room in the sump amounts to 10.75g; so if 5.6g falls when the return pump is off, there should be more than enough room in the sump to hold the overflow.

 

Since the skimmer is recirc, it doesn't require any amount of water depth. I put two 2" baffles around it, one by the filter sock, and the other to the left side of the skimmer. I was also wondering if a single 4" baffle by the filter sock might work better, helping to stop more microbubbles initially, but I was worried the falling water from the 4" baffle to the 1" water level the skimmer would be at might be too loud?

 

Lastly, is there anyway to reduce the # of baffles in this setup? I need the baffles to total 24" in combined length, as that's what the acrylic sheets come in from Home Depot. (IE 3 8" baffles would work, or 2 10" and 1 4"; or in this current plan, 3 8", 2 10", and 2 2").

 

Advice/Comments?

[Coral Hind]

I would make sure the far left baffle by the mag pump is not too high above the water level or the falling water will create bubbles that will get sucked into the pump and in turn into the display. That baffle really doesn't even need to be above the water line.

[Ryan S]

I would make sure the far left baffle by the mag pump is not too high above the water level or the falling water will create bubbles that will get sucked into the pump and in turn into the display. That baffle really doesn't even need to be above the water line.

 

Thank you. I can definitely adjust that. I am going to drill a hole for the float valve where you are talking about. I can drill the hole at the 10" mark then, so the water just flows over evenly as you've suggested. 10" is a pretty high water level in a tank that's only 12" tall, but I wanted this chamber to be high due to the fluctuation here b/c of evaporation. You don't think 10" would be a problem here do you?

[Chad]

A couple of things. First off, the way you have it, water level in your skimmer section would be the same as your fuge level since the water has to rise high enough to flow over the baffles... I would probably put the return in the center, and the skimmer/fuge on the ends and run the fuge from a separate water source rather than have all the flow through your sump forced through the fuge.

 

Also, like David said, the baffle can be much lower, it just needs to direct waterfall bubbles to the surface. give me just a second to draw, I'll show you the tweaks I mean.

[BowieReefer84]

A couple of things. First off, the way you have it, water level in your skimmer section would be the same as your fuge level since the water has to rise high enough to flow over the baffles... I would probably put the return in the center, and the skimmer/fuge on the ends and run the fuge from a separate water source rather than have all the flow through your sump forced through the fuge.

 

Also, like David said, the baffle can be much lower, it just needs to direct waterfall bubbles to the surface. give me just a second to draw, I'll show you the tweaks I mean.

 

 

something like this?